Validating the efficiency of γ-Al2O3/La0.6Sr0.4Co0.2Fe0.8O3-δ double-layer electrolyte for low temperature solid oxide fuel cell

Perovskite La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3+δ (LSCF) as a promising cathode material possessed overwhelming electronic conduction along with certain ionic conductivity. Its strong electron conduction capability hinder the application of pure-phase LSCF as electrolyte in semiconductor membrane fuel cell (SMFC). In order to constrain the electron transport and take advantage of the decent ion conduction of LSCF, a thin layer of γ-Al 2 O 3 with insulating property was added as an electron barrier layer and combine with LSCF to form a two-layer structure electrolyte. Through adjusting the weight ratio of LSCF/γ-Al 2 O 3 to optimize the thickness of double layers, an open circuit voltage of 0.98 V and a maximum power density of 690 mW/cm 2 was received at 550 °C. At the same time, SEM, EIS and other characterization technology had proven that the LSCF/γ-Al 2 O 3 bi-layer electrolyte can work efficiently at low temperature. The advantage of this work is the application of double-layer (γ-Al 2 O 3 /LSCF) structure electrolyte to instead of mixed material electrolyte in low-temperature solid oxide fuel cells. Structural innovation and the using of insulating materials provided clues for the further development of SMFC. • This work proposes new bi-layer electrolyte in low-temperature solid oxide fuel cell. • Wide band gap oxide γ-Al 2 O 3 is used as an electron barrier layer. • The short-circuit phenomenon of LSCF as an electrolyte in low-temperature solid oxide fuel cells has been improved. • The device avoids high temperature sintering and can still obtain good performance. • The lower operating temperature eliminates the thermal matching between the bi-layer electrolyte.